The invention relates to a cold-start assisting device for controlling the supply of an auxiliary fluid, especially an ether containing auxiliary fluid, to the inlet lines of a combustion engine with ignition and starting circuits, which assisting device operates a valve at a connecting line for the auxiliary fluid by means of a starting switch and a control switch during starting operation and by means of the control switch after a successful start.
An apparatus or device to facilitate engine starting with low temperatures is known from U.S. Pat. No. 4,202,309, wherein auxiliary fluid is injected by means of a temperature responsive starting switch. The function of this arrangement is limited to the starting procedure.
In U.S. Pat. No. 2,679,837 an apparatus is made known, with which not only during the starting, but rather also after a successful start, for example during unsteady running or idling of the combustion engine, auxiliary fluid in the form of heated fuel can be injected by means of a control switch.
The invntion addresses the problem of preventing by simple means a careless or intentional operation of a cold-start assisting arrangement which provides auxiliary starting fluid injection to a stalled engine, thereby avoiding the related dangers to the engine.
These problems are solved according to the present invention by providing that the cold-start assisting device control switch has an auxiliary working contact for a further switch position, which is connected with one of the terminals of a dynamo or generator, which auxiliary contact exhibits a relatively negative electrical potential with a non-operating generator and a positive electrical potential during operation of the generator. Thus, auxiliary injection is automatically prevented since, even with the control switch pushed to an auxiliary injection position with a stalled engine, the absence of electrical potential at the generator terminal in the circuit prevents injection.
Through the inventive security measures, during tapping (light touching) of the control switch with engaged ignition and a stalled engine, injection of the auxiliary fluid is avoided simply, whether the tapping of the control switch is intentional or unintentional. A disturbance of the motor by injecting auxiliary fluid under these conditions is thereby avoided.
The special switch connection has the further advantage that an injection of the auxiliary fluid during a push-start of the engine with defective batteries is possible since the pushing will operate the generator and raise the voltage at its terminal so as to permit the auxiliary injection.
These and further objects, features, and advantages of the present invention will become more obvious from the following description when taken in connection with the accompanying drawing which shows, for purposes of illustration only, a single embodiment in accordance with the present invention.